Quick-coupling device for tools on diggers or similar machines

ABSTRACT

Quick-coupling device ( 1,2 ) for tools on machines, especially on agricultural, transport, lifting, digging and earth-moving machines, which is characterized in that it comprises an adaptor ( 2 ), joined to the articulated arm of the machine via at least one master pin ( 7 ), made up of a base plate ( 17 ) which is essentially flat and side walls ( 10 ) whose outer surfaces ( 10 ) have, at least partly, slopes which converge in the direction of coupling of the adaptor ( 2 ) to the tool ( 3 ), said adaptor ( 2 ) having movable fixing means ( 13 ), the device also comprising coupling means ( 1 ) in the tool ( 3 ) to be coupled, which contain rigid hooks ( 5,5′,6,6′ ) for receiving the ends of the master pin ( 7 ) joining the adaptor ( 2 ) and the articulated arm of the machine and side walls ( 9 ) whose inner surfaces ( 9 ′) have, at least partly, converging slopes which match the slopes of the outer surfaces of the adaptor, the side walls also having perforations ( 8 ) for receiving and holding, by locking, the movable fixing means ( 13 ) of the adaptor ( 2 ), so that in the coupling position a wedge or locking effect is produced between the adaptor walls ( 10 ) and the tool ( 3 ), and the fixing means ( 13 ) is introduced in the perforations ( 8 ) of the side walls ( 9 ) of the tool, the hooks ( 5,6 ) and perforations ( 8 ) also being positioned in such a way that the tool ( 3 ) couples with the adaptor ( 2 ) in one of two positions turned 180° with respect to a vertical axis.

TECHNICAL FIELD OF THE INVENTION

The invention refers to a quick and reversible coupling device for toolssuch as shovels, buckets, hammers, clamps, grippers, etc., on machines,especially agricultural, transport, lifting and earth-moving machinessuch as diggers, back-diggers or similar.

BACKGROUND OF THE INVENTION

Various quick replacement or coupling devices currently exist for toolson machines used to move earth. Said devices comprise a first body withcoupling elements, such as fixed claws, which clamp onto master pins orcoupling axles on a second body, which is separate from the tool whichis to be coupled to the machine.

Some embodiments of known coupling devices also use secondary movablecoupling mechanisms. This is the case, for example, in patents ES2102548 and WO 95/16831.

ES 2102548 describes a quick-coupling device in which the movableelements of the first body are two locking shafts, which are essentiallycylindrical, and the free ends of these are in the shape of a truncatedcone, the angle of the cone matching that of the openings on the lockingplate of the second body, which is separate from the tool, and also saidlocking plate is sloped, on its rear part, which fits the correspondingslope of the contact surface of the first body, thus helping the contactsurfaces of the first and second bodies to lock together.

WO 95/16831 has a coupling device also made up of two bodies, the firstof these being separate from the tool and the second being separate froman articulated arm of the machinery. In the embodiment, as well ashaving a coupling axle in one of the two bodies and claws for graspingthe coupling axle on the other body, the device has a movable element onone of the bodies, which is wedge-shaped, which operates in conjunctionwith a fixed element on the other body working in the form of a hook, insuch a way that in the coupling position, the wedge moves beneath thehook under the action of a piston or similar.

Due to the heavy-duty work the tools used are subjected to in this typeof machinery, the coupling devices known suffer a high level of wear andtear for which the coupling devices, or one of their parts, have to bechanged or replaced frequently, and the machines must be stopped tocarry out any change required to avoid the possible breakdown orbreakage of the parts which suffer the most wear. The use of saiddevices therefore makes them more costly than desired and themaintenance required is very expensive.

The wear and tear suffered on the devices is caused especially by theconcentration of loads on small surfaces and the tolerance or play thatexists between the different bodies making up the device, and with everymovement the tool makes there is unwanted friction which, over time,reduces the initial setting conditions, producing undesirable movementin the matching of parts.

In addition, a common problem of known embodiments, is the difficultyinvolved in coupling up the different bodies making up the device (afirst body separate from the arm of the machine and a second oneseparate from the tool), since assembly is difficult when the machineoperator, manoeuvring the arm from the cabin of the machine, has tomatch up the two parts or bodies of the device. This manoeuvre is madeeven harder when the tool is resting on uneven ground or if its slope isdifferent from that of the ground under the machine on whose articulatedarm the particular tool is to be coupled.

Similarly, in the embodiments known, master pins or dowel pins are usedfor joining up the body onto the end of the articulated arm of themachine, while said body and the tool are coupled via a third master pinand the other claws on the other body. Such configurations produce evenmore wear and tear of the parts as well as increasing the weight of thequick-coupling devices.

Lastly, the devices known are not suitable for coupling in differentpositions, so that if the tool is to be coupled the other way round,turned 180° with respect to a vertical axis, a second tool is requiredwhose means of gripping are configured in reverse, and for this twodifferent tools are needed, which therefore results in a greaterinvestment in material.

It is also noted that there is no system whereby the machine operatorcan know if the bodies have been coupled together correctly and if themovable coupling elements are in the required position for the machineto function.

EXPLANATION OF THE INVENTION

To provide a solution to these problems, an explanation will be given ofthe quick and reversible coupling device for tools on machines,especially transport and lifting machines, earth-moving or diggingmachines, such as diggers, back-diggers or similar, said machinescomprising an articulated arm at the end of which the tool is coupled sothat it cannot move.

The device is, in essence, characterized in that it comprises:

an adaptor joined to said articulated arm via at least one master pinand, in one of its ends, made up of a base which is essentially flat andside walls, said adaptor also has fixing means, which moveperpendicularly through said side walls; and

means of coupling on the tool, which comprise of rigid hooks forreceiving the ends of the master pin and side walls with perforationsfor receiving and holding, by locking, the movable fixing means of theadaptor,

the outer surfaces of the side walls of the adaptor and/or innersurfaces of the side walls of the coupling means having, at leastpartly, converging slopes suitable for gradually housing the adaptor inthe coupling means of the tool, so that, in the coupling position, thebase of the adaptor is in contact with a corresponding essentiallyflat-surfaced part of the tool, or coupling means, and the fixing meansis introduced in the perforations of the side walls of the tool.

According to a preferred embodiment, the outer surface of the side wallsof the adaptor have sloping guiding surfaces around the protruding endsof at least one master pin, said surfaces being cone-shaped with animaginary axis being coincident with the longitudinal axis of the masterpin.

In another preferred embodiment, the outer surfaces of the side walls ofthe adaptor have, at least partly, slopes which converge in thedirection of coupling of the adaptor on the tool, insofar as the innersurfaces of the side walls of the coupling means have, at least partly,converging slopes which match the slopes of the outer surfaces of theadaptor, which produces a wedge or locking effect between the slopingsurfaces of the adaptor and those of the coupling means in the couplingposition.

In accordance with another characteristic of the invention, the couplingmeans of the tool comprise four rigid hooks located on the four ends ofthe side walls of the coupling means, positioned so that the master pincan be coupled with both the pair of front hooks and the pair of rearhooks, so that the tool can be coupled and fixed to the adaptor in twodifferent positions, at an angle of 180° with respect to one another.

There are preferably two perforations on each side wall, opposite eachother, and equidistant from the hooks on the same wall and axiallyaligned in the coupling position with the movable fixing means throughthe side walls of the adaptor, and the master pin being coupled in thepair of front hooks or in the pair of rear hooks, due to the symmetricalpositioning of the perforations, the movable fixing means of theadaptor, upon moving, are introduced in said perforations of thecoupling means of the tool, the coupling means and the tool being joinedin any of the possible coupling positions.

According to another characteristic of the invention, the perforationsof the side walls of the tool have a section which gets smaller towardsthe outside, which matches with another section which gets smallertowards the outside of the fixing means to be housed inside of theseduring the coupling position.

In a preferred embodiment, the coupling means have in their font andrear parts means for housing the adaptor, which respectively haveopposite sloping surfaces, and the end of the tool opposite to themaster pin has at least one matching chamfer with a sloping surface sothat, in the coupling position, the chamfer or chamfers can rest,without any play, on the sloping surfaces of the housing means locatedon the front or rear part of the coupling means, depending on thecoupling position.

In accordance with another characteristic of the invention, at least onefixing means has a rod whose free end is visible from the outside, sothat it can be determined visually whether the fixing element is housedinside the corresponding perforation.

BRIEF DESCRIPTION OF THE DRAWINGS

The attached drawings illustrate, as a non-limitative example only, twoforms of embodiment of the quick-coupling device for back-digger toolson machines, or similar ones to the object of the invention. In saiddrawings:

FIG. 1 is a perspective view of a first form of embodiment of thedevice, in which the adaptor and the tool are uncoupled;

FIG. 2 is a front elevational view of the device in FIG. 1, in which theadaptor and the tool are uncoupled;

FIG. 3 is a perspective view of the device in FIG. 1, in which theadaptor and the tool are coupled;

FIG. 4 consists of three front sectional views of three possiblevariations for one of the side walls of the coupling means for thedevice in FIG. 1;

FIGS. 5 and 6 are both elevational side views of the two couplingpositions of a shovel on the arm of a back-digger machine;

FIG. 7 is a perspective view of a second form of embodiment of theinvention device, in which the adaptor and the tool are uncoupled;

FIG. 8 is also a perspective view of the device in FIG. 7, in which theadaptor and tool are in the process of being coupled;

FIG. 9 is a front, diagrammatical view of the adaptor and the couplingmeans according to the form of embodiment in the previous FIGS. 7 and 8;and

FIG. 10 is a perspective view of the device in FIG. 7, in which theadaptor and the tool are coupled, the adaptor being in a position turned180° with respect to the coupling position in the previous FIGS. 7 and8.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first form of embodiment of the devicebeing the object of the invention, in which the adaptor 2 and the tool 3are uncoupled.

The device comprises an adaptor 2 joined to the articulated arm 4 of themachine (represented in FIG. 5), via master pins 7 and 7′, and is madeup of a base 17 and side walls 10.

On the base 17 are movable fixing means 13, which together with the endsof the master pin 7 make the adaptor 2 couple securely to any tool 3which has respective coupling means 1, whether this is a shovel, as inFIG. 1, a bucket, hammers, clamps, grippers or pallet-fork lifters, etc.

As can be seen in FIG. 1, the tool 3 does in fact have coupling means 1which comprise side walls 9 whose ends are configured in the shape ofrigid hooks 5, 5′, 6 and 6′, which can receive and grip, at leastpartly, the ends of the master pin 7.

Similarly, the side walls 9 have perforations, 8 a and 8 b, which canreceive and hold, by locking, the movable fixing means 13 of the adaptor2.

The positioning of the perforations 8 a and 8 b in the sides 9, and thepositioning of the hooks 5, 5′, 6 and 6′ in the side walls 9, islongitudinally and transversally symmetrical so that, regardless ofwhich hooks receive the master pin 7 of the adaptor 2, the movable means13 of the adaptor 2 will be axially aligned with perforations 8 a or 8 bof the side walls 9 of the tool 3.

In FIG. 1, the hooks 5 and 5′, situated on the same end of the sidewalls 9, are about to receive the ends of the master pin 7. At thisstage, the base 17 will sit on the corresponding surface 17′ of the tool3, and the fixing means 13 will remain axially aligned with theperforations 8 b of the opposite end of the side walls 9. Similarly, ifthe tool 3 is turned 180° with respect to a vertical axis, the hooks 6and 6′ will receive the ends of the master pin 7, and the movable fixingmeans 13 of the adaptor 2 will remain axially aligned, this time, withthe perforations 8 a on the opposite end, closest to the hooks 5 and 5′.

Special attention should be paid to the fact that the master pin 7 usedto join the adaptor 2 to the articulated arm 4, is the same one used tocouple the tool 3 to the adaptor via the hooks 5, 5′ or 6, 6′, since inknown embodiments, there is no case of the master pin 7 being shared insuch a way, with different master pins being used for coupling theadaptor 2 to the tool 3 and for joining said adaptor 2 to thearticulated arm 4 of the machine. In the invention device, the number ofparts and the number of worn elements are reduced, which is an importantimprovement on the durability, weight and play of the devices known.

In FIG. 2 another characteristic of the invention device can be seen. Insaid figure, a front view of the coupling means 1 of the tool 3 isshown, in which it can be seen how the side walls 9, with respect to thedirection of coupling of the adaptor 2, indicated by the arrow in FIG.2, have converging slopes, so that the upper ends of the walls 9 arefurther apart than those of their lower ends.

Such positioning greatly helps the coupling between the adaptor 2 andthe tool 3, because the walls 9 of the tool 3 act as a guide for theside walls 10 of the adaptor 2 introduced inside the space within thetwo walls 9 of the tool 3. This greatly helps the coupling of the toolin situations where before it was very difficult to carry out suchmanoeuvre, for example, for the coupling of a tool 3 which is on unevenground, and leaning with respect to the horizontal surface or to thesurface on which the machine is standing.

In addition, the walls 10 of the adaptor 2 also have a slope whichmatches the slope of the walls 9 of the tool 3, producing an automaticfit between the adaptor 2 and the tool 3 during coupling and, oncecoupled, when pressure is transmitted to the tool 3, in this case theshovel, the pressure is not concentrated exclusively on the claws 5, 6and the master pin 7, but is distributed between the walls 9 and 10 ofboth main bodies, producing a locking effect between its respectivecontact surfaces 9′, 10′, which greatly allows the pressure to bedistributed over the device and lengthens its useful life, since wearand tear by friction, due to unnecessary play or concentrations ofpressure on small surfaces, are reduced.

It should be pointed out that it is not necessary for the sides walls 10and 9 to entirely comprise of converging slopes, as long as the innersurfaces 9′ of the side walls 9 and the outer surfaces 10′ of their sidewalls 10, are at least partly sloped.

FIG. 4 a is thus a section view of a side wall 9 of the tool 3,according to the embodiment in FIG. 1, in which the whole wall issloping. FIG. 4 b shows a second variation in which only the innersurface 9′ of the side wall 9 is sloping and, lastly, FIG. 4 c shows athird form of embodiment in which only the part 9′ of the inner surfaceof the side wall 9 is sloping. This latter embodiment shows a side wall9 with one or several ribs which run inwards, (this is towards theopposite side wall), in this case being the surface 9′ of the ribs whichshows the desired slope. Obviously, the outer surfaces 10′ of the sidewalls 10 can also be configured in the same way as the inner surfaces ofthe tool 3, the variations explained above also being possible.

In FIG. 3 the tool 3 is coupled to the adaptor 2, and the fixing means13 of the adaptor, upon moving perpendicularly through the walls 10, canbe introduced inside the perforations 8 b of the side walls 9 of thetool 3. When this happens, the movements of the adaptor 2 transmittedthrough the articulated arm 4 of the machine (shown in FIGS. 5 and 6)are transmitted to the tool 3 as if it were the same solid mass.

The perforations 8 can have various different forms although all mustfit the shape of the fixing means 13 for insertion inside them. Both theperforations 8 and the fixing means 13 can thus have round or polygonalsections, and may also get smaller towards the outside, producing awedge effect upon introducing the fixing means 13 in the perforations 8.

According to the embodiment in the drawings, the fixing means 13 can bemoved by the action of a hydraulic system 12, which comprises at leasttwo pistons 14 activated by an electric valve. In this way, the movementof the fixing means 13 can be controlled from the cabin of the machineor from any other place which has hydraulic-fluid or electricalcommunication with the hydraulic system 12.

This system will also have a retention valve for retaining the fixingmeans 13 inside the perforations 8 in case the hydraulic system losespressure.

Obviously, the actuating mechanism of the fixing elements 13 can also bemechanical or even manual, and can incorporate safety devices to blockthe position of the fixing means 13 inside the perforations 8 a or 8 b.

As a safety element, the side walls 10 of the adaptor 2, at the oppositeend to that of the master pin 7, are in the shape of a hook 18, whoseopen or eye section, in the coupling position, coincides with the hooks5 and 5′ or 6 and 6′, depending on the coupling position, allowing asafety master pin to pass through them, joining the adaptor 2 and thetool 3. The hook configuration 18 will also, if necessary, mean that thehooks can act as lifting hooks, so that through their open end theadaptor can be suspended by a supporting cable.

FIGS. 5 and 6 show the arm 4 of a back-digger machine or similar, inwhose end the adaptor 2 is fixed respectively via the master pins 7 and7′, and in which the tool 3, in this case a shovel, is coupled to theadaptor, in two different positions, turned 180° respectively withrespect to one another and according to an imaginary axis of rotation19.

A second form of embodiment of the quick-coupling device for tools ondigger machines or similar is shown in FIGS. 7, 8 and 9. In saidfigures, for simplification, the same numerical references have beenused to indicate the same or similar components with respect to thedescription of the first form of embodiment in FIGS. 1 to 6.

As can be seen in FIG. 7, the device comprises an adaptor 2, joined tothe articulated arm of the machine via master pins 7 and 7′, and is madeup of a base 17 which is essentially flat and side walls 10. The ends ofthe master pin 7, located at the front end of the adaptor 2, are to bereceived and partially gripped by the front hooks 5, 5′, or by the rearhooks 6, 6′, of the coupling means 1 of the tool 3. In this way, and inthe same way as in the previous embodiment, the device is reversiblesince the tool 3 can be coupled to the adaptor 2 using the couplingmeans 1, in two positions which are both turned 180° with respect to animaginary vertical axis 19.

In FIG. 7, in which the adaptor 2 and the tool 3 are separate, it canalso be seen that the coupling means 1 have housing means 21, 21′ and22, 22′ respectively on their front and rear parts, for the adaptor 2.Said housing means consist in protruding extensions in the form ofprismatic wedges. These prismatic wedges have sloping surfaces 24, thoseof the forward wedge being directly opposite those of the opposite endof the coupling means 1, with which said sloping surfaces of the frontwedges 21, 21′ are facing the corresponding sloping surfaces of the rearwedges 22 y 22′. While the adaptor 2 is being coupled, thischaracteristic makes the end of the adaptor 2 opposite to the master pin7 rest on said sloping surfaces, and the adaptor 2 is forced to movetowards its front end, so that the master pin 7 fits securely in thehooks of the locking means and the base 17 is in contact with acorresponding portion, with an essentially flat surface 17′, of the tool3 or the coupling means 1.

To improve the effect produced by the sloping surfaces of the wedges 21,21′ and 22, 22′, the adaptor 2 has respective chamfers on each of itsside walls 10, with slopes which match those of the wedges, so that inthe coupling position the chamfers rest, without any play, on thesloping surfaces of the front or rear wedges, depending on thepositioning of the coupling.

In FIG. 8, the ends of the master pin 7 are introduced in the hooks 5and 5′ and the rear wedges 22 and 22′ have still not yet been supportedby the chamfers 23 of the adaptor 2. In this figure, the movable fixingmeans 13 can be seen positioned at the same distance with respect to themaster pins 7 and 7′, while the perforations 8 of the side walls 9 ofthe coupling means 1 are at the distance with respect to the front hooks5, 5′ and rear hooks 6, 6′. In this way the fixing means 13 of theadaptor, upon being moved perpendicularly through the walls 10 of theadaptor, can be inserted inside the perforations 8 of the side walls 9of the coupling means 1 to transmit the movements of the adaptor 2 tothe tool 3, whatever the positioning of the coupling, in the same way asthat of the first form of embodiment.

By having the same shape as the fixing means 13 getting smaller towardsthe outside, to match the section with the perforations 8, uponintroducing the fixing means in the perforations, a wedge effect isproduced, which forces the adaptor 2 to move towards the tool 3 and, dueto the effect of the sloping surfaces of the wedges 22 and 22′(depending on the positioning of the coupling in FIGS. 6 and 7) theadaptor 2 is also forced to move in a direction towards its front end,ensuring the correct coupling between itself and the tool 3.

As can be seen in FIG. 9, and different from the first form ofembodiment, the inner surfaces of the walls 9 of the coupling means arenot sloped at all and are perpendicular to the surface 17′ of the tool3. Nevertheless, in order to guide the coupling of the adaptor and tohelp introduce it between the walls 9 of the coupling means 1, the outersurface of the side walls 10 of the adaptor 2 have sloping guidingsurfaces 10′. In the example given in the drawings, said guidingsurfaces are positioned around the protruding ends of the master pins 7and 7′, and are cone shaped whose imaginary axis coincides with thelongitudinal axis of the master pins. In this way, whatever the slope ofthe adaptor 2 with respect to the tool 3 during the coupling process,the guiding surfaces 10′ which are in contact with the walls 9 of thecoupling means converge in the direction of coupling and act as guidesto ensure the adaptor 2 is correctly introduced between said walls 9.

In FIG. 10, in which the adaptor 2 is coupled to the tool 3 via thecoupling means 1, it can be seen that the inventor also provided for theadaptor 2 to have at least one perforation 25, positioned level with therear master pin 7′, and in one of the side walls 10, which communicatesthe upper surface of said wall 10 with the perforation for housing themaster pin 7′. This master pin 7′ has its own respective perforationswhich are axially aligned with the perforations 25, enabling the end ofthe safety master pin, introduced through the perforations 25 of theadaptor 2, to be housed. In this way, the safety master pin prevents themaster pin 7′ from moving, securing its position in the adaptor 2, whichjoins the adaptor to the mechanical arm 4 of the machine.

Also in FIG. 10, the adaptor 2 is coupled to the tool 3 in a positionwhich is turned 180° with respect to the coupling position shown in theprevious FIGS. 7 and 8, without needing to change or replace the tool 3with another whose coupling means can be adjusted to the new couplingpositioning. Using the same adaptor 2 and the same tool 3, the lattercan be coupled in different positions, greatly improving what otherknown devices can offer.

1. A quick-coupling device (1,2) for coupling tools (3) on machines,especially agricultural, transport, lifting, digging and earth-movingmachines, said machines comprising an articulated arm (4) having adistal end portion to which a rigid tool (3) is couplable, wherein thequick-coupling device (1,2) comprises: an adaptor (2) joinable to saidarticulated arm (4) through at least one master pin (7), the adaptorcomprising a substantially flat base plate (17) with first side walls(10), and displaceable locking means (13) protruding transversallythrough the first side walls (10); and coupling means (1) attachable tothe tool (3) and comprising rigid hooks (5,5′,6,6′) engageable with saidat least one master pin (7) and second side walls (9) with openings (8)aligned with the displaceable locking means (13) of the adaptor (2) whenthe device is in use in its locking position, wherein the first sidewalls (10) of the adaptor (2) are, in use, locked between the secondside walls (9) of the coupling means (1), wherein at least a part of thefirst side walls (10) comprises first inclined surface portions (10′)converging in the coupling direction and/or at least a part of thesecond side walls (9) of the coupling means (1) comprise convergingsecond inclined surface portions (9′), such that the base plate (17) ofthe adaptor (2) is in contact with a corresponding substantiallyflat-surfaced portion (17′) of the tool (3) when the adaptor (2) islocked onto the coupling means (1) and tool (3), respectively, byengaging the displaceable locking means (13) with the openings (8) ofthe coupling means (1), wherein the coupling means (1) of the tool (3)comprise four rigid hooks (5,5′,6,6′) located on the four ends of thesecond side walls (9) of the coupling means (1), a pair of rigid hooks(5,5′) being located at a front portion and a pair of rigid hooks (6,6′)being located at a rear portion, said rigid hooks (5,5′,6,6′) beingpositioned so that the at least one master pin (7) is able to be coupledwith both the pair of front hooks (5,5′) and with the pair of rear hooks(6,6′), so that the tool (3) is able to be coupled and fixed to theadaptor (2) in two different positions, at an angle of 180° with respectto one another.
 2. The device of claim 1, wherein the outer surface ofthe side walls (10) of the adaptor (2) have sloping guiding surfaces(10′) around the protruding ends of at least one master pin (7,7′), saidsurfaces being cone-shaped with an imaginary axis being coincident withthe longitudinal axis of the master pin (7,7′).
 3. The device of claim1, wherein at least a part of the first side walls (10) comprises firstinclined surface portions (10′) converging in the coupling direction andat least a part of the second side walls (9) of the coupling means (1)comprise converging second inclined surface portions (9′), saidconverging second inclined surface portions (9′) matching the firstinclined surface portions (10′) so as to achieve a wedge effect betweenthe first inclined surface portions (10′) and the converging secondinclined surface portions (9′).
 4. The device of claim 1, wherein thereare two perforations (8) on each side wall (9), opposite each other, andequidistant from the hooks on the same wall (9) and axially aligned inthe coupling position with the movable fixing means (13) through theside walls (10) of the adaptor (2), and the master pin (7) being coupledin the pair of front hooks (5,5′) or in the pair of rear hooks (6,6′),due to the symmetrical positioning of the perforations (8), the movablefixing means (13) of the adaptor (2), upon moving, are introduced in thesaid perforations (8) of the coupling means (1) of the tool (3), thecoupling means (2) and the tool (3) being joined in any of the possiblecoupling positions.
 5. The device of claim 4, wherein the perforations(8) of the side walls (10) of the tool (3) have a section which getssmaller towards the outside, which matches with another section whichgets smaller towards the outside of the fixing means (13) to be housedinside of these during the coupling position.
 6. The device of claim 1,wherein the coupling means (1) have in their front and rear parts meansfor housing the adaptor (2), which respectively have opposite slopingsurfaces, and in that the end of the tool (2) opposite the master pin(7) has at least one matching chamfer with a sloping surface so that, inthe coupling position, the chamfer or chamfers can rest, without anyplay, on the sloping surfaces of the housing means located on the frontor rear part of the coupling means (1), depending on the couplingposition.
 7. The device of claim 1, wherein at least one fixing means(13) has a rod (16) whose free end is visible from the outside, so thatit can be determined visually whether the fixing element (13) is housedinside the corresponding perforation (8).
 8. (canceled)